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ENVIROGUARD Stern-tube Sealing System for Marine, Naval and Energy Markets

Interview: Wärtsilä Marine Seals and Bearings


On the fringes of the Euronaval exhibition in Paris late last year, MONCh had the opportunity to quiz Vah Ly, Technical Sales Support Engineer – Naval Segment for Wärtsilä Marine Seals and Bearings on the company’s ENVIROGUARD product.


VL: Wärtsilä ENVIROGUARD is a stern-tube sealing system or mechanical face seal designed to prevent sea water from entering the vessel at the point where the propulsion shaft line protrudes from the ship. We have developed it with the commercial and military markets in mind.

MONCh: How does it work?

VL: Fundamentally, Wärtsilä ENVIROGUARD is a water-lubricated sealing solution consisting of a static mounting flange, flexible watertight spring assembly, static composite sealing face and rotating bronze counter-face. The static mounting flange contains inflatable seals to facilitate maintenance and repair afloat. The flexible spring assembly is designed to cater for the extremes of radial and axial shaft movements, including shock impact. This flexibility ensures the sealing interface, between static and rotating surfaces, remains closed in all operating environments, preventing sea water ingress into the vessel. The low-wear interface materials, corrosion-resistant metal components and robust flexible spring assembly make it suitable for both blue-water and abrasive water conditions.

MONCh: What is the difference between the ENVIROGUARD MA and MD ranges?

VL: The MA is a fully split seal, which can be fitted with the shaft already in place. The MD is a partially split seal that can only be installed once the shaft line has been uncoupled or removed. Both contain a static face and dynamic seat, and have replaceable split wearing components to ease overhaul and maintenance processes.

MONCh: What are ENVIROGUARD’s principal benefits?

VL: Proven design and world-class components enable it to perform for longer in some of the harshest environments – making it a stellar product for the marine and energy markets. With
this essential piece of equipment in place, ship operators can fulfil operational requirements in the knowledge that their vessel is working to its full potential.

MONCh: ‘Optimisation is a word much used in reference to Wärtsilä solutions: what drives you to continual improvement?

@VL: Our customers drive everything that we do and enthuse us to perfect our products year on year. In listening to our customers, we have been able to develop unparalleled sealing solutions that really do perform as intended. That’s massively important.”

MONCh: Thank you.

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